title: D-dimer level and the risk for thrombosis in systemic lupus erythematosus.
abstract: OBJECTIVE
  Patients who have systemic lupus erythematosus (SLE) and manifest antiphospholipid antibodies (APA) are at increased risk for thrombosis; however, it is difficult to predict who will clot. This study tested the hypothesis that peak D-dimer level measured routinely during follow-up identifies whether a hypercoagulable state is developing and, therefore, the patient is at increased risk for thrombosis.
  
  
  METHODS
  One hundred consecutive patients who had SLE with recurrent activity (71% renal SLE) and were evaluated for or enrolled in the Ohio SLE Study were studied. D-dimer testing was done annually and usually at SLE flare or other serious illness. When D-dimer was elevated, evaluation for thrombosis (large vessel, small vessel, or Libman-Sacks) was undertaken. Mean follow-up was 37.5 +/- 15 SD months.
  
  
  RESULTS
  Of those with peak D-dimer <0.5 microg/ml (n = 46), 0% thrombosed, 33% had APA. Of those with peak D-dimer 0.5 to 2.0 microg/ml (n = 19), 6% thrombosed, 44% had APA. Of those with peak D-dimer >2.0 microg/ml (n = 36), 42% thrombosed, 76% had APA. The most common causes of elevated D-dimer in the absence of demonstrable thrombosis were SLE flare and systemic infection. D-dimer levels were usually elevated for several months before thrombosis.
  
  
  CONCLUSIONS
  Patients with SLE and normal D-dimer levels are at low risk for thrombosis, irrespective of APA status. Those with persistent unexplained elevated D-dimer levels, particularly when >2.0 microg/ml, are at high risk for thrombosis.
authors.affiliation: Department of Pathology, Ohio State University Medical Center, Columbus, Ohio 43210, USA.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Wu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Birmingham
authors.forename: Brad
authors.initials: B
authors.lastname: Rovin
authors.forename: Kevin V
authors.initials: KV
authors.lastname: Hackshaw
authors.forename: Nabil
authors.initials: N
authors.lastname: Haddad
authors.forename: Douglas
authors.initials: D
authors.lastname: Haden
authors.forename: Chack-Yung
authors.initials: CY
authors.lastname: Yu
authors.forename: Lee A
authors.initials: LA
authors.lastname: Hebert
mesh_terms: D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000097:blood; D015415:Biomarkers / Q000097:blood; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000209:etiology*; D013997:Time Factors; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D017152:Antibodies, Antiphospholipid; D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D